[Preventive iridotomy--a prospective study]

To evaluate the mid-term efficiency of laser peripheral iridotomy (LPI) in preventing intraocular pressure (IOP) increase and angle closure in the fellow eye after acute primary angle closure glaucoma.

prospective, noncomparative, interventional case series--29 consecutive cases with acute primary angle closure glaucoma on presentation were enrolled in the study in 2001. Mean follow-up time: 14 months (12-18 months).

assessment of IOP and gonioscopy of the fellow eye; LPI of the fellow eye within 24h of presentation. IOP assessment of the fellow eye thrice a day until discharge. Gonioscopy of the fellow eye at discharge. One month later: visual field; optic nerve head evaluation of the fellow eye after pupil dilation; IOP monitoring until pupil recovery. IOP assessment on a monthly basis.

2 patients presented with bilateral angle closure attack; 2 patients presented with angle closure attack of the second eye, which had not received adequate preventive treatment; 1 patient developed angle closure of the fellow eye immediately after the initial gonioscopy but was promptly managed with LPI; 7 patients had IOP > 21 mm Hg of the fellow eye on presentation, required medication after LPI but did not develop acute angle closure during the follow-up; 17 patients had normal IOP of the fellow eye, remained normal during the follow-up and did not require medication.

LPI is highly efficient in preventing acute angle closure in the fellow eye; in the eyes that were normal on presentation, LPI also prevents later IOP increase.